1. Field of the Invention
The present invention relates to a reflected fluorescence microscope which is utilized to observe a living tissue or cell in the fields of medicine, biology, and the like, and which has an excitation filter and an absorption filter and, more particularly, to a reflected fluorescence microscope in which the excitation wavelength and the absorption wavelength can be adjusted.
2. Description of the Related Art
Generally, reflected fluorescence microscopes are widely used in medicine, biology, and other fields to detect a protein, a gene, and the like marked with a fluorescent label on a living tissue or cell.
In recent years, as various types of fluorochromes have been developed, the reflected fluorescence microscopes are used particularly to study the mutual positional relationship among specific substances and the localization of a specific substance in a cell by means of multiple stain using various types of materials as the fluorescent labels.
When specimens stained with various fluorescent materials are to be observed using a reflected fluorescence microscope of this type, a fluorescent filter set consisting of an excitation filter, a dichroic mirror, and an absorption filter is prepared for each specific fluorochrome, and an optimum combination of the excitation and absorption wavelength regions is obtained by selectively using the fluorescent filter sets, thereby observing the specific fluorochrome.
In this manner, the conventional reflected fluorescence microscope has fixed excitation and absorption wavelength regions for each fluorescent filter set. Therefore, in order to observe various types of specimens stained with fluorochromes with the optimum excitation and absorption wavelength regions, a considerably large number of fluorescent filter sets are needed. Then, the number of components is increased, leading to an increase in manufacturing costs.
When the mutual positional relationship among the multiple fluorochromes that stain the fluorescent specimen is to be studied, the respective fluorescent images of the fluorescent specimen must be recorded on a photograph or a video memory in multiple exposure. Therefore, the conventional reflected fluorescence microscope is not suitable for detection of fluorochromes having high discoloration speeds or detection of the mutual positional relationship among the fluorochromes by using time as a parameter.
When the fluorescent filter sets are selectively used, off-centering of the observation optical system occurs depending on the component precision of the dichroic mirror, the absorption filter, and the like, and an error occurs in the mutual positional relationship detected from the fluorescent image.